Wariyapola Sri Sumangala (Sinhala:වාරියපොල ශ්‍රි සුමංගල) was a Buddhist monk who lived in the early 19th century in Sri Lanka (then known as Sinhale). He was an Anunayaka of the Asigiriya Chapter. Sri Sumangala is known for taking down the Union Jack and re-hoisting the Sinhalese lion flag,before the convention that handed over control of the country to the British in 1815. Later during the rebellion of 1818, he removed the Tooth Relic of the Buddha from the Temple of the Tooth, and handed it over to the leaders of the rebellion. He was arrested and convicted for treason the same year.

Sumangala was born as Bamunakotuve Ralahamige Kirihami, in the village of Wariyapola in the Kurunegala district. His father's name was Herath Mudiyanselage Bamunakotuve Rala. Kirihami was ordained as a Buddhist monk in the Asgiriya Chapter of the Siam Nikaya by a monk named Navinne Dhammadassi, and named Wariyapola Sri Sumangala (Sri Sumangala of Wariyapola). He later obtained Upasampada as well. He quickly rose through the hierarchy of the Nikaya, and was eventually appointed an anunayaka—a sub-chief monk second to the mahanayaka— of the Asgiriya Chapter. He was the chief monk of the Sailathalaarama in Wariyapola, now named after him as Sri Sumangala Pirivena Raja Maha Viharaya.

In 1815, Sinhalese leaders drew up the Kandyan Convention with the British, handing over control of the country to them. On the day this agreement was to be signed (2nd March 1815) at the Temple of the Tooth, a British soldier had taken down the Sinhalese flag and hoisted the Union Jack. Sri Sumangala had taken it down and raised the Sinhalese flag again,[2] declaring that until the convention was signed the country still belonged to the Sinhalese and their flag will fly until that time. This "Sinahalese flag" is believed to be the lion flag used by the last rulers of the country, and this event is mentioned in the books recording the history of the Asgiriya Chapter.

In 1818, a rebellion started in the uplands of the country against the British rule. With the outbreak of this rebellion, Venerable Wariyapola Sumangala, who was the Anunayake of Asgiri Chapter, was "in service" at the inner shrine room of the Sri Dalada Maligawa when the British took over Kandy from the Chieftains, took no time to "spirit" away the Sacred Tooth Relic from the Sri Dalada Maligawa, hiding it in the seam of his robe, and went into hiding in Hanguranketa. He later handed it over to Keppetipola Disawe, who was leading the rebellion.

The possession of the Tooth Relic was traditionally regarded as a symbol of the right to rule the country, and the acquisition of it was a large morale boost to the rebels, who intensified their activities after that. British was all out to secure the Sacred Tooth Relic.The British Officer Shootbraid took the Sacred Relic into custody and brought the Thera to Kandy in November 1818 and recovered the Tooth Relic, which they ceremonially brought into Kandy again. The rebellion ended soon after this.

Sri Sumangala was convicted for treason and imprisoned in Jaffna with 23 other prisoners. He was released on 13 April 1821 by order of the then Governor of Ceylon. He did not come back to his Temple at Sudhumpola or to his hometown Wariyapola Temple. It has been reported later that Venerable Wariyapola Sumangala Thera lived the life of an ascetic in Jaffna for the rest of his life, despising the Sinhala people for their ungratefulness.